Illinois’ reputation for political corruption is legendary, and well-earned. I have no problem with being the butt of jokes about shady politicos — we’ve put in centuries of work toward that rep — but it does raise an idle question.

Is Illinois the worst?

It’s hard to measure what “the most corrupt state” is, although data crunchers often pop open the Justice Department’s yearly “Report to Congress on the Activities and Operations of the Public Integrity Section” and give it a try.

If you go by number of convictions for corruption from 1976 to 2015, Illinois’ 2,033 conviction put it at No. 5. But, other than New York jumping ahead of Texas and California, the top five is just a list of the five largest states in order.

State

Convictions, 1976-2015

2015 population estimate

New York

2,766

19.7M

California

2,730

38.4M

Texas

2,090

26.5M

Florida

2,060

19.6M

Illinois

2,033

12.9M

Looking at convictions per capita puts Louisiana at the top, Mississippi at No. 2, and Illinois at No. 7, but there are problems here too.

Between Mississippi and Illinois are four of the seven smallest states in the Union. No. 7 Illinois has 17 times the number of corruption case as No. 6 North Dakota, but 18 times the population. Is North Dakota more corrupt or just really tiny?

State

Convictions, 1976-2015

2015 population estimate

Convictions per 100,000

Louisiana

1,107

4.6M

23.9

Mississippi

633

3M

21.2

South Dakota

171

843,000

20.3

Alaska

145

733,000

19.8

Montana

183

1M

18.0

North Dakota

123

722,000

17.0

Illinois

2,033

12.9M

15.8

Population isn’t the only problem with trying to use these numbers to make rankings. This is a list of federal prosecutions. That omits any corruption charges prosecuted at the state or local levels, and skews in favor of states that have better-funded and better-staffed U.S. attorney’s offices.

Personal ambition and politics also play. U.S. attorneys have incredible discretion in terms of which cases they pursue and allot resources to, whether it’s Patrick Fitzgerald taking down governors and police torture squads or Acting U.S. Attorney for North Dakota Kevin Schieffer showing up with 35 FBI agents, 20 National Guardsmen and, according to witnesses, a full face of makeup for the TV crews to make a big splash seizing SUE the T-rex in the 1990s.

But that’s a story for another day.

U.S. attorneys looking to make a name for themselves — like prosecutor-turned-governor the James R. Thompson Center glass UFO is named for — are more likely to pursue big-fish political cases. More troubling, U.S. attorneys appointed by Republican presidents are more likely to go after Democratic officials and vice versa, according to a 2012 study published by Oxford University Press. But there’s a bigger issue.

By nature, any conviction-crunching only includes illegal corruption, not the day-to-day favor-trading and gamesmanship you or I would consider foul. While conviction statistics are vital for understanding corruption, looking solely at the numbers would be a look at corruption that doesn’t consider patronage, sweetheart deals, hiring your buddies and the general you-scratch-my-back-and-I’ll-scratch-yours that makes the bulk of shady politics.

“Who sells his influence should stop it, An honest man will only swap it,” as Ambrose Bierce wrote in 1899.

Nor would it include any crook who got away with it. You can figure the murder rate by counting the bodies, but acts of public corruption, when successful, are invisible.

We’re left then with opinions. Perception indices are problematic — who cares what someone thinks is going on? — but when trying to quantify crimes the powerful want to hide, the opinions of insiders are really some of the better indicators we have.

A 2014 survey from Harvard’s Edmond J. Safra Center for Ethics asked about 1,000 reporters working political beats across the nation for their takes on their own state’s corruption. The 280 who responded put Kentucky at the top and Illinois as the second most corrupt state in the Union.

The low response rate and inherent self-selection bias make this one pretty flawed as well. For example, no reporters from Louisiana responded to the survey, so that historically corrupt state didn’t even make the list.